Question: Who is the person that was doctoral adviser of Paul Krugman?
Paraphrase: Paul Krugman's doctoral adviser name was?
SPARQL (Wikidata):  select distinct ?sbj where { ?sbj wdt:P184 wd:Q131112 . ?sbj wdt:P31 wd:Q5 } 
Answer: Elise Brezis, Lant Pritchett, Matthew J. Slaughter, Richard Baldwin, Philip Lowe, Michael Kende, Donogh Colm McDonald, Luca Barbone, Charles Bram Cadsby, Won Am Park, Israel Gutierrez-Guerrero, Salvador Valdes-Prieto, Harry Leon Foster, Edward Hudson Gardner, Tahir Raza Shah Andrabi, Robert Brandon Kahn, Vincent Rodolphe Koen, Sadao Nagaoka, C. Keith (Charles) Head, Krishnamurthy Narayanan, Stephen Yung-li Jen, Eiichi Tomiura, Michael J. Chapman, Raul Alejandro Livas Elizondo, Gustavo Enrique Cañonero, Ludwig Boris Chincarini, Zhichao Yuan, Mikhail Mikhailovich Klimenko, Kai Lilaka Chan